Microsoft plans to add pop-up blocking features to Internet Explorer next year as part of its Service Pack 2 update for Windows XP, a move that would go far toward stamping out the Web advertisements.

Darin Linnman, a Microsoft spokesman, said that the company plans to add the pop-up blocking feature to an updated version of Explorer with Service Pack 2 (SP2) when it's released in the first half of next year. But one caveat, he said, is that Microsoft will be gathering customer feedback that will be weighed as part of the final decision to add the feature.

"I can confirm SP2 will include an update to IE that adds pop-up blocking," Linnman said.

By adding pop-up blocking tools to IE, Microsoft will belatedly join a host of other Web browser makers that let people avoid flashy pop-ups, or advertising windows that appear over or behind requested Web pages. Opera, Mozilla and Netscape--all of which have only a minor share of the total browser market--give users the option to seamlessly block intrusive advertising while surfing the Web. Because Microsoft dominates the browser market, it could greatly influence people's ability to remove the ads with ease.

"A lot of marketers may be mad at Microsoft (because of it), but it could go a long way to killing the pop-up problem. It's just an easier solution to turn it off in the browser" rather than to download anti-pop-up software, said Richard Smith, an Internet security consultant.

Internet service providers have also responded to a consumer outcry against pop-ups in recent years despite potential losses from advertising sales. EarthLink led a trend among ISPs to introduce anti-pop-up tools in 2002. AOL upped the ante last year by promising not to sell pop-ups to third parties, and it released technology to fend off the ads in AOL version 8.0 last October. Microsoft matched AOL's move in its own Internet access software. And just this September, Yahoo and SBC Communications updated their joint Internet access services to include a pop-up ad blocker.

The moves were the result of deep consumer loathing of pop-ups. About 88 percent of broadband users and 87 percent of dial-up users in North America find that pop-ups interfere with their Web surfing experience, according to Forrester Research. But only 15 percent of consumers have downloaded ad-blocking software. Having a tool in IE could make avoiding the ads simpler.

"It's a recognition that pop-ups are very disruptive to user experience--they're the most hated type of advertising," said Charlene Li, principal analyst for Forrester.